Association between napping and cognitive impairment: A systematic review and meta-analysis

Wu Fang; Shi Le; Wang Han; Xu Peng-Jiao; Yu Shuai; Zhang Rui-Ling; Lu Lin; Xu Ya-Hui

doi:10.1016/j.sleep.2023.09.022

Association between napping and cognitive impairment: A systematic review and meta-analysis

Sleep Med. 2023 Nov:111:146-159. doi: 10.1016/j.sleep.2023.09.022. Epub 2023 Sep 25.

Authors

Wu Fang¹, Shi Le², Wang Han¹, Xu Peng-Jiao¹, Yu Shuai¹, Zhang Rui-Ling¹, Lu Lin³, Xu Ya-Hui⁴

Affiliations

¹ Department of Sleep Medicine, Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.
² Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Chinese Academy of Medical Sciences Research Unit (No. 2018RU006), Peking University, Beijing, China.
³ Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Chinese Academy of Medical Sciences Research Unit (No. 2018RU006), Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Beijing, China. Electronic address: linlu@bjmu.edu.cn.
⁴ Department of Sleep Medicine, Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, China. Electronic address: 18737354427@163.com.

PMID: 37776585
DOI: 10.1016/j.sleep.2023.09.022

Abstract

Study objectives: Increasing evidence suggests that napping is associated with cognitive impairment and dementia, but the conclusions are inconsistent. Moreover, the extent of the risk is uncertain. We therefore conducted a systematic review and meta-analysis to quantify the connection between napping and cognitive impairment.

Methods: We performed a systematic search of PubMed, EMBASE, Web of Science, and Cochrane Library for studies that were published up to June 2023, and assessed associations between napping and cognitive impairment. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated as the effect sizes for all studies. Heterogeneity and potential publication biases were assessed.

Results: A total of 4535 papers were retrieved, with 20 reports assessing the relationships between napping and cognitive impairment. Pooled analysis indicated that napping was associated with dementia (OR = 1.14; 95% CI: 1.07-1.21). Importantly, we found that those napping longer than 30, 45, and 60 min/day were 35%, 41%, and 40%, respectively, more likely to have an increased risk of cognitive impairment (30 min: OR = 1.35; 95% CI: 1.24-1.48; 45 min: OR = 1.41; 95% CI: 1.27-1.58; 60 min: OR = 1.40; 95% CI: 1.26-1.56). North America and Europe showed that associations existed between napping and cognitive impairment (North America: OR = 1.15; 95% CI: 1.04-1.27; Europe: OR = 1.13; 95% CI: 1.08-1.18).

Conclusions: This meta-analysis indicated associations between long napping durations and cognitive impairment or dementia, suggesting that longer napping might be a potential risk factor of adverse cognitive outcomes.

Keywords: Cognitive impairment; Dementia; Meta-analysis; Napping.

Publication types

Review